Carnarvon is the current High Chaplain (Master of Sanctity) of the Flesh Tearers Chapter of Space Marines. He serves as the warden of that Chapter's infamous Death Company, a special unit whose members are consumed by the permanent, debilitating psychosis known as the Black Rage.
High Chaplain Carnarvon is called the "Watcher of the Lost," for he is the lone Flesh Tearer entrusted with the sacred duty of commemorating every member of the Chapter who dies in combat or ultimately succumbs to the debilitating psychosis known as the Black Rage. He alone bears the terrible responsibility to watch over the remaining 400 Battle-Brothers of the Flesh Tearers Chapter for the onset of the Black Rage. He has occupied this position for nearly 250 standard years and it is whispered by many that the strain of watching so many of his friends and comrades descend into this dreaded affliction has started to take its toll on his sanity. Carnarvon has the final word as to who is to be inducted into the Flesh Tearers' Death Company and who amongst these afflicted brethren must be permanently incarcerated in the Tower of the Lost because they have fallen so far into madness that even he cannot control them. When not in combat, Carnarvon spends most of his time within the Lost Tower, watching over his charges, ostensibly to find a path that will allow them to rejoin the Chapter. However, his constant secrecy currently has a great many of the Flesh Tearers questioning his motives.
- Index Astartes I, ""Blood Frenzy: The Flesh Tearers Space Marine Chapter" by Matthew Sprange and Gav Thorpe, pg. 50